1. Field
Aspects of the present invention relate to the field of electric power lines. More specifically, aspects of the present invention relate to the field of monitoring from electric power lines.
2. Description of the Related Art
As a transmission line is pushed to carry more energy, the conductor heats and, because of the added heat, the transmission line sags. The traditional method of determining the conductor sag has been derived by a set of operating conditions. For example, knowing the conductor's physical size, its manufacturer's rated current capacity, current flow, the approximate still air ambient temperature, wind speed, and time of day, the system operator could “approximate” how much the conductor sags.
This approximation, however, can provide a false sense of security. For instance, the Northeast Blackout of 2003 was the result of an overloaded transmission line flashing over to ground by sagging into vegetation below the transmission line. The system operator had no knowledge that the transmission line was in danger as it was being operated within the system standard operating conditions.
Therefore, there is a need for precisely and automatically monitoring the location (to determine, for example, the sag) of a power transmission line in relation to nearby objects.